Electronic products have become an integral part of our daily lives. This has created a consistent if not increasing expectation for new features, higher speed, more data, improved portability, etc. These demands have driven the development of electronic technology to reduce size, improve utility, and increase performance of the integrated circuit devices in an ever-increasing range of products such as cell phones, music players, televisions, and automobiles.
Packages of components such as semiconductor circuits, transistors, diodes and other electronic devices must also become smaller and thinner with more functions and connections. In packaging components, the need for connecting leads largely influences package dimensions. Many attempts have been made to create a surface mount type of packaging for semiconductor devices having a lead-less structure in which connecting leads are not needed.
Area array packages such as a ball grid array (BGA) require more materials and processing than more established technologies such as lead frame technology. The BGA package requires a substrate with traces, vias, and solder balls typically preformed for a specific range of integrated circuit device dimensions, input/output (I/O) count, and I/O functions.
Typically, area array packages use a laminate substrate to achieve higher lead counts while lead frame packages use less expensive materials and simpler processes resulting in higher reliability. For example, laminate is not able to withstand pressure cooker tests (PCT) in the same way as lead frame packages. Corrosion tests such as PCT have been a limitation of laminate packages.
Lead frame packaging relies on spacing between connecting leads of a lead frame to be very small in order to connect a device having many signal pins. Width or thickness of each lead should also be reduced but leads bend easily causing unwanted open or short circuits. Unfortunately, package size is often relegated to relatively large dimensions and spacing.
Current high-count lead frame packages require a relatively high number of fabrication steps making fabrication process complicated thereby increasing manufacturing costs. Attempts to provide projected portions at the bottom of a package often require forming metal film on the surface of the projected portions are complicated and costly.
In other attempts, etching processes are required to pattern metal foil for the die pads and leads further complicating manufacturing processes. It is also necessary to use a base apparatus for supporting the metal foil when patterning. This base apparatus is unnecessary after manufacturing the semiconductor integrated circuit device but still increases costs and complexity.
If metal foil is patterned after packaging the semiconductor device, the base apparatus becomes unnecessary. However, since the etching process is typically performed by wet etching, it is necessary to provide water resistant protection for the package including the semiconductor device when the etching is performed. Therefore, these manufacturing processes are also complicated and increase costs.
Yet other attempts require a pattern layer between the frame-like structures and column-like structures. These additional components increase manufacturing complexity and costs. The, number of manufacturing processes steps alone can significantly increase manufacturing processing costs.
Current attempts have many issues often requiring additional components such as metal film, electrodes of metal foil, column-like structures, and pattern layers. These components are pre-designed and manufactured into specific patterns and sizes with additional design and fabrication for different applications. Inventory and manufacturing are complicated and costly.
Thus, a need still remains for improving numbers of leads, compatibility, flexibility, reliability, yield, and manufacturing throughput to control costs and improve performance in systems for integrated circuit packages with isolated leads.
In view of the ever-increasing commercial competitive pressures, along with growing consumer expectations and the diminishing opportunities for meaningful product differentiation in the marketplace, it is critical that answers be found for these problems.
Additionally, the need to save costs, improve efficiencies and performance, and meet competitive pressures, adds an even greater urgency to the critical necessity for finding answers to these problems.
Solutions to these problems have been long sought but prior developments have not taught or suggested any solutions and, thus, solutions to these problems have long eluded those skilled in the art.